Seizures are fairly uncommon in cats, but the episode can be quite disturbing for owners, even though they do not cause pain to the cat. Seizures are mostly caused by epilepsy, but fortunately, the incidence of feline epilepsy is much less than the estimated 3% incidence in dogs.
Epilepsy can be primary or secondary. Primary epilepsy is difficult to prove, as it is associated with primary encephalopathy, which is a disorder of the brain. In such cases, the cat has recurrent episodes of seizures but shows no abnormalities in physical or neurological examinations, including advanced imaging techniques like an MRI or a CAT scan. Even examination of the cerebrospinal fluid fails to reveal anything regarding the cause behind the seizure. The normal practice is to consider it a case of primary epilepsy once all other causes are eliminated.
Secondary epilepsy is classified as recurrent seizures that occur due to known causes, such as a head injury, infectious diseases, or a brain tumor. Some of the metabolic diseases like diabetes, liver, and kidney disorders can cause seizures. These are seen less in cats that in dogs. Recurrent feline seizures are more often than not associated with a head trauma and infections. There are certain conditions that are typical to cats like feline infectious peritonitis, feline leukemia virus, and feline immune-deficiency virus that are suspected if the cat suffers from frequent seizures. Cryptococcosis, (a fungal infection characterized by nodular lesions that appear first in the lungs and spreads to the nervous system) and the rabies virus are the two other infections that are suspected. Toxoplasmosis and infections caused by parasites rarely causes feline seizures. These are suspected only if they are accompanied by suppression of the immune system.
About 20% of cats who suffer from a sudden onset of feline seizures are diagnosed with a condition where the blood supply to the brain is restricted. This is a condition that is similar to a stroke. Cancer, including brain tumors like meningioma and lymphoma, is another possible cause behind feline epilepsy.
Feline epilepsy is rarely seen in very young cats. The first seizure normally appears in two to three-year-old cats, with varying intensities.
- Petit mal - Epilepsy characterized by paroxysmal attacks of brief clouding of consciousness that may be accompanied by other abnormalities, and lasts for up to one minute.
- Grand mal - Epilepsy in which the attacks involve loss of consciousness and tonic muscle contractions followed by generalized jerking. Grand mal seizures usually extend up to five minutes.
- Status epilepticus - A condition of continuing attacks of epilepsy that continues for hours without intervals of consciousness.
Status epilepticus is the most severe epileptic seizure that can cause brain damage and may lead to death of the cat. The milder manifestations, petit and grand, do not threaten a cat’s life. However, these also need to be reported to the veterinarian immediately since they can pose serious danger to the life of the cat.
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